  <!DOCTYPE html>
  <html lang="en">
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width='device-width', initial-scale=1.0">
    <title>Document</title>
  </head>
  <body>
    <h1>一级标题</h1>
    <h2>二级标题</h2>
    <h3>三级标题</h3>
    <h4>四级标题</h4>
    <h5>五级标题</h5>
    <h6>六级标题</h6>
    <p>段落标签</p>
  </body>
  </html>